.\"     $NetBSD: sa_setconcurrency.2,v 1.4 2005/09/05 21:57:35 yamt Exp $
.\"
.\" Copyright (c)2004 YAMAMOTO Takashi,
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.\" ------------------------------------------------------------
.Dd September 6, 2005
.Dt SA_CONCURRENCY 2
.Os
.Sh NAME
.Nm sa_setconcurrency
.Nd increase the number of virtual processors
.\" ------------------------------------------------------------
.Sh LIBRARY
.Lb libc
.\" ------------------------------------------------------------
.Sh SYNOPSIS
.In sa.h
.Ft int
.Fn sa_setconcurrency \
    "int concurrency"
.\" ------------------------------------------------------------
.Sh DESCRIPTION
.Fn sa_setconcurrency
is used to increase the number of scheduler activation virtual processors
used by the process.
.Fn sa_setconcurrency
increases the number of virtual processors, i.e., execution concurrency,
up to
.Fa concurrency .
However,
.Fn sa_setconcurrency
won't try to allocate more virtual processors than there are physical
processors on the system.
.Pp
Scheduler activation should be enabled by
.Fn sa_enable
beforehand.
.\" ------------------------------------------------------------
.Sh RETURN VALUES
On success,
.Fn sa_setconcurrency
returns the number of newly added virtual processors.
Otherwise, a value of \-1 is returned and
.Va errno
is set to indicate the error.
.\" ------------------------------------------------------------
.Sh SEE ALSO
.Xr pthread 3
